The study examined a nuisance abatement program in San Diego, which pressured landlords with drug problems on their rental property to improve their management practices. One intervention involved landlords receiving a letter from the police describing the enforcement and offering assistance. The other intervention involved landlords meeting with a narcotics detective under threat of nuisance abatement, which, if it occurred, would result in a civil suit against the property owner. Landlords then conducted several activities accordingly, such as evicting drug offenders and renovating places.

How was the intervention evaluated?

From June through November 1993, all residential rental properties (N=121) that were subject to some form of drug enforcement (e.g., search warrant based raid and undercover buy) were randomly assigned to either one of the two treatments described above or a control group (where nothing further was done by the police following the initial enforcement action). The Drug Abatement Response Team (DART), which was in charge of implementing the program, recorded the actions conducted at each property and the subsequent actions of the landlords. To determine the treatment effect, the researchers collected police data regarding reported crime incidents for each site for a 30-month follow up period. They aggregated the data into five six-month intervals and compared the crime rates across all three groups. The authors also conducted regression analysis to control for the pre-treatment differences.

What were the key findings?

Results showed more evictions of drug offenders for both treatment groups compared to the control group, and more evictions for the meeting group than the letter group. Property owners in the meeting group also had a sizeable reduction (86%) in reported crime within six months of the intervention. Regression analysis suggests a 60% reduction in crime for the meeting group over the entire 30-month period. There is also some evidence in support of a crime reduction effect of the letters, which was less conclusive.

What were the implications for law enforcement?

The authors suggest that when police and code enforcement officials meet with property owners following drug enforcement, they can significantly reduce crime. The authors also assert the importance of the actions of place managers in impacting crime rates at a location.

Where can I find more information about this intervention, similar types of intervention, or related studies?